1. Field of the Invention
The present invention relates to a device test handler, and more particularly, to a device test handler which facilitates room temperature as well as elevated or lower temperature testing of a logic device; and a method for operating the same.
2. Background of the Related Art
In general, a semiconductor device undergoes a test for inspection of defects after completion of fabrication on a production line. The device test handler is employed in testing various logic devices, such as QFP, BGA, PGA, SOP and the like, which are mostly non-memory semiconductor packages. During such testing, the device is placed in a tray which travels through the test machine. At some point, the logic device is tested at a test part. The logic devices are then unloaded onto trays after classifying the devices into different grades according to a result of the test. Different classifications of logic devices are loaded into different trays.
However, the related art device test handler has the following problems. First, the frequent pickup and placing of logic devices by the related art device test handler causes breakage to the expensive logic devices during testing, and also prolongs index times.
Second, the related art device test handler has a test part that temporarily holds the logic devices to be tested in test sockets for a time period until the testing is completed. There is an indexing device for automatic and continuous transportation and loading of the logic devices to be tested from input trays into the test socket, and for unloading the tested devices from the test socket to an unloading tray. However, the indexing device in the related art device test handler is quite complicated. For example, the indexing device disclosed in JP Laid Open Patent No. H10-82830 (Mar. 31, 1998) has a system in which two contact hands reciprocate in two directions for loading and unloading the logic devices in succession. This system was intended to reduce the index time compared to other indexing devices without increasing a number of components of the indexing device. However, this indexing device, which transports the logic devices in both directions, requires a separate device for continuous and simultaneous placing and picking up of the logic devices to/from two stages loaded on shuttles on both sides of the indexing device. As a result, the whole system of the related art device test handler becomes complicated because the separate device is very complicated and difficult to operate.
Accordingly, the present invention is directed to a device test handler and a method for operating the same that substantially obviates one or more of the problems, limitations and disadvantages of the related art.
An object of the present invention is to provide a device test handler, which can conduct room temperature or elevated temperature testing, and a method for operating the same, which can reduce frequent picking and placing of logic devices. As a result, damage to the logic devices is minimized, and an index time is reduced.
Another object of the present invention is to provide an indexing device for a device test handler, which is simple, and which can minimize an index time and make device testing easy without provision of a separate device placing/picking up device.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description which follows, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a device test handler embodying the invention includes a loading part movably fitted on a base of the device test handler. The loading part moves trays in forward and backward directions, each of the trays having logic devices to be tested placed therein. Multiple loading shuttles are movably fitted on the base for transferring the logic devices through the test handler. A pre-heating part may be used for pre-heating the logic devices on the shuttles as the shuttles pass therethrough when it is required to test the logic devices at an elevated temperature. The test handler includes a test chamber having one or more test sockets, each of which is configured to receive, hold, and test the logic devices. An indexing device of the test handler is configured for successive transferring of the logic devices from one of the loading shuttles into the test socket, and for transferring the tested logic devices from the test socket to one of the unloading shuttles. A heat supply means of the test handler is used for supplying a high temperature heat to the test socket when the devices must be tested in a hot state. The logic devices are classified according to a result of the test. A transporting device of the test handler is used for transferring the logic devices from trays in the loading part to one of the shuttles, and for transferring the devices from one of the shuttles, after testing, into trays or an unloading part. The logic devices are placed in different trays of the unloading part by the transporting device depending on their classification.
A device test handler embodying the invention may further includes a buffer part for temporary storage of logic devices determined to be defective before transferring the logic devices to the unloading part.
The transporting device includes a guide frame fitted to cross over the base of the device test handler. A loading picker is movably fitted at one side of the guide frame and is configured to move along the guide frame. The loading picker is used to transfer logic devices to be tested from input trays in the loading part onto a loading shuttle. A first unloading picker is also movably fitted to the guide frame to move along the guide frame. The first unloading picker transfers the tested logic devices from an unloading shuttle onto respective trays in an unloading part, and onto a buffer part. A second unloading picker is also movably fitted to the guide frame to move along the guide frame. The second unloading picker is used to transfer logic devices from the buffer part to a defective device tray in the unloading part.
The pre-heating part includes a heating plate for heating the loading shuttles while the loading shuttles are placed and carried thereon. Because the logic devices can be preheated as the shuttles move along the heating plate, there is no need to pick and place the devices into a preheating chamber. Thus, a test handler embodying the invention reduces device picking up and placing times compared to prior art devices, and facilitates room temperature and high temperature testing.
The unloading part includes a plurality of good device trays for holding logic devices determined by the test to be good devices. The unloading part also includes a plurality of retest device trays for holding logic devices classified for retesting, and a plurality of defective device trays for holding logic devices classified as defective.
The device test handler further includes a loading shuttle direct transporting device for transporting a loading shuttle directly to the test chamber without forcing the loading shuttle to pass through the pre-heating part. This can occur when the logic devices are to be tested at room temperature. The loading shuttle direct transporting device allows testing to be carried out more efficiently as a moving path of the loading shuttle becomes shorter when the devices are to be at room temperature.
The device test handler further includes a tray distributing device for distributing empty trays from the loading part to the unloading part after all the logic devices are transferred from the input trays. The tray distributing device simplifies operations and reduces the need for operator action, as empty trays can be re-circulated on the device test handler.
The indexing device in the testing part includes a pair of opposing frames fitted to crossover the loading shuttle, the test socket and the unloading shuttle. A first index head and a second index head are movably fitted in parallel to the frames for alternately repeating a process of transferring logic devices from a loading shuttle to the test sockets, loading the devices into the sockets, and transferring the devices from the test sockets to an unloading shuttle. A first driving means and second driving means are provided for respectively moving the first index head and the second index head in a rotational manner along the frames. First vertical driving means and second vertical driving means are provided for respectively moving the first index head and the second index head in up and down directions.
Each of the first driving means and second driving means includes a motor fitted to one side of the frame. A threaded driving rod is rotatably fitted in parallel to the frame and is configured to rotate as the motor is driven. A supporting block thread is coupled to the threaded driving rod for moving along the threaded driving rod as the threaded driving rod rotates. A guide member is coupled to the supporting block in parallel to the threaded driving rod for guiding a movement of the supporting block as the supporting block is moved by the threaded driving rod.
Each of the first vertical driving means and second vertical driving means includes a vertical motor, and a threaded vertical driving rod coupled to the vertical motor. An elevating member is coupled to the threaded vertical driving rod for moving up and down as the threaded vertical driving rod rotates. A supporting member is coupled to the elevating member, and a front portion the first index head or the second index head is fitted thereto. A guide member is coupled to the supporting member for guiding a vertical movement of the supporting member as the supporting member is moved by the threaded vertical driving rod.
A method for operating a device test handler embodying the invention includes the steps of: (1) loading a tray having devices to be tested on a loading part; (2) transporting the devices loaded on the loading part, by means of a loading picker, into a loading shuttle; (3) pre-heating the devices on the loading shuttle as the loading shuttle passes through a pre-heating part; (4) transporting the loading shuttle, after it has passed through the pre-heating part, to a test chamber; (5) loading the devices on the loading shuttle in the test chamber into one or more test sockets, by means of the indexing device, testing the logic devices, and unloading the devices from the test sockets to an unloading shuttle; (6) classifying the tested devices on the unloading shuttle according to a result of the testing; (7) transferring the tested devices determined good or to be retested into trays for the good devices or the devices to be retested by means of a first unloading picker; (8) transferring and temporarily storing the devices determined defective on a buffer part, and (9) transferring the devices from the buffer part to the tray for defective devices in the unloading part by means of a second unloading picker.
If the devices are to be tested at room temperature, a method embodying the invention could eliminate step (3) so that the loading shuttle is transported to the test chamber directly by means of a direct transporting device without passing through the pre-heating part after the devices are loaded on the loading shuttle.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.